The present invention relates to visualizing the ribs in computed tomography (CT) volumes, and more particularly to detecting “up-vectors” of ribs in 3D CT volumes to unfold the rib cage into a 2D image.
Ribs can be affected by a variety of disorders, such as traumatic, metabolic, and congenital disorders. CT imaging can help visualize lesions on the ribs. However, the multi-slice scan generated in a 3D CT volume provides a large amount of data that is difficult and tedious for physicians to examine. Therefore, computer aided detection is important in helping doctors to visualize the lesions on the ribs.
A computer aided detection system that can help doctors locate rib lesions easily and accurately is desirable. An important aspect of such a system is the ability to unfold the CT volume data from 3D to 2D. This is because small lesions are typically difficult to identify and locate in the 3D CT volume, but easier to locate in a corresponding 2D unfolded image. In addition, there may be different interpretations for the same lesion caused by the transverse sections of ribs with respect to either the long or short axes of the rib. Accordingly, a method that correctly unfolds the 3D rib cage into 2D can not only save examination time, but also decrease the ambiguity of interpreting the CT data.